Detection of lesions in planar mammogram is a different task, predominantly due to the masking effect of superimposed parenchymal breast patterns. Tomographic imaging can provide the radiologist with image slices through the three dimensional (D.) breast possibly reducing this masking effect. The goal of the proposed research is to investigate the feasibility OD using an amorphous silicon, flat-panel image for volumetric compound tomography (CT) of the breast. Our hypothesis is that dedicated CT mammography using state-of-the-art digital detectors can provide high quality images and three dimensional visualization of breast tissue, with a radiation dose approximately equivalent to that given in screening mammography. We propose to investigate the characteristics of such a system by integrating a commercial prototype, flat panel image, with an optical bench plate containing precision rotational and transnational stages. This would allow the acquisition of projection imaged by rotating phantoms in angular steps over 360 degrees. We also propose to theoretically investigate optional CT mammography system configurations using mathematical models of single and noise propagation through the flat panel detector, and realistic models of the lesion detection task in breast imaging. Design and acquisition parameters such as tomographic sampling requirements, imaging geometry, x-ray converter characteristics, and x-ray energy spectrum incident on the braes will be investigated. Previous reports have suggested great potential for tomographic breast imaging. To evaluate improvements in tomographic mammography, if any, we plan to compare lesion detection accuracy using human observer studies and stimulates images generated with planar mammography, tomosynthesis, and CT . an important component of these studies will be the use of realistic models for lesions and breast tissue. These models will be determined based on the statistical characterization of surgically removed lesion and breast tissue specimens.